Merge branch 'jc/strbuf-add-lines-avoid-sp-ht-sequence'

Merge branch 'jc/strbuf-add-lines-avoid-sp-ht-sequence'

The commented output used to blindly add a SP before the payload
line, resulting in "# \t<indented text>\n" when the payload began
with a HT.  Instead, produce "#\t<indented text>\n".

* jc/strbuf-add-lines-avoid-sp-ht-sequence:
  strbuf_add_commented_lines(): avoid SP-HT sequence in commented lines